#c { position: relative;}
#a { position: absolute; left: 10; top: 10; font-size: 12px; font-family: 宋体; }
#b { position: absolute; left: 10; top: 10; font-size: 12px; font-family: 宋体; -moz-opacity:0;opacity: 0;filter: alpha(opacity=0); }
#logindev{
    margin-top: 220px; 
  }
  .panel-primary {
    border-color: #f0ad4e;
}